Long-term survival after endovascular and open repair of unruptured abdominal aortic aneurysm.

BACKGROUND: The aim of this study was to examine patterns of 10-year survival after elective repair of unruptured abdominal aortic aneurysms (AAAs) in different patient groups. METHODS: Patients having open repair or endovascular aneurysm repair (EVAR) in the English National Health Service between January 2006 and December 2015 were identified from Hospital Episode Statistics data. Postoperative survival among patients of different age and Royal College of Surgeons of England (RCS) modified Charlson co-morbidity score profiles were analysed using flexible parametric survival models. The relationship between patient characteristics and risk of rupture after repair was also analysed. RESULTS: Some 37 138 patients underwent elective AAA repair, of which 15 523 were open and 21 615 were endovascular. The 10-year mortality rate was 38·1 per cent for patients aged under 70 years, and the survival trajectories for open repair and EVAR were similar when patients had no RCS-modified Charlson co-morbidity. Among older patients or those with co-morbidity, the 10-year mortality rate rose, exceeding 70 per cent for patients aged 80 years. Mean survival times over 10 years for open repair and EVAR were often similar in subgroups of older and more co-morbid patients, but their survival trajectories became increasingly dissimilar, with open repair showing greater short-term risk within 6 months but lower 10-year mortality rates. The risk of rupture over 9 years was 3·4 per cent for EVAR and 0·9 per cent for open repair, and was weakly associated with patient factors. CONCLUSION: Long-term survival patterns after elective open repair and EVAR for unruptured AAA vary markedly across patients with different age and co-morbidity profiles.

ANTECEDENTES: El objetivo de este artículo fue examinar los patrones de supervivencia a 10 aáos tras reparación electiva de aneurismas de la aorta abdominal sin rotura (abdominal aortic aneurysms, AAA) en diferentes grupos de pacientes. MÉTODOS: Se identificaron pacientes sometidos a reparación abierta (open repair, OR) o reparación endovascular (endovascular aneurysm repair, EVAR) del aneurisma en el Sistema Nacional de Salud Inglés entre enero de 2006 y diciembre de 2015, a partir de los datos del Hospital Episode Statistics. Se analizaron la supervivencia postoperatoria entre los pacientes de diferentes edades y los perfiles de comorbilidad con la puntuación de Charlson modificada del Royal College of Surgeons of England (RCS) utilizando modelos de supervivencia paramétricos flexibles. También se analizó la relación entre las características de los pacientes y el riesgo de rotura tras la reparación. RESULTADOS: Un total de 37.138 pacientes fueron sometidos a reparaciones electivas de AAA, de las cuales 15.523 fueron reparaciones abiertas y 21.615 endovasculares. La mortalidad a los 10 aáos fue del 38% para los pacientes de edad inferior a los 70 aáos, y las curvas de supervivencia de la OR y EVAR fueron similares cuando los pacientes no tenían comorbilidad con el Charlson modificado del RCS. Entre los pacientes de edad avanzada y aquellos pacientes con comorbilidad, la mortalidad a los 10 aáos aumentó, excediendo el 70% para los pacientes de más de 80 aáos de edad. La media de los tiempos de supervivencia superior a 10 aáos para OR y EVAR fueron similares dentro de los subgrupos de pacientes de edad avanzada y más comorbilidad, pero las curvas de supervivencia se hicieron cada vez más diferentes, con la OR mostrando un mayor riesgo a corto plazo en los primeros 6 meses pero tasas de mortalidad a los 10 aáos más bajas. El riesgo de rotura mas allá de los 9 aáos fue 3,4% para EVAR y 0,9% para la reparación abierta, con una débil asociación con los factores inherentes a los pacientes. CONCLUSIÓN: Los patrones de supervivencia a largo plazo tras OR y EVAR electivas para AAA sin rotura varían notablemente entre pacientes con perfiles de edad y comorbilidad diferentes.

Population-based study of mortality and major amputation following lower limb revascularization.

BACKGROUND: The aim of this study was to estimate separate risks of major lower limb amputation and death following revascularization for peripheral artery disease (PAD) using competing risks analysis. METHODS: Routinely collected data from Hospital Episode Statistics (HES) were used to identify patients who underwent endovascular or open lower limb revascularization for PAD in England from 2005 to 2015. The primary outcomes were major lower limb amputation and death within 5 years of revascularization. Cox proportional hazards and Fine-Gray competing risks regression were used to examine the competing risks of these outcomes. RESULTS: Some 164 845 patients underwent their first lower limb revascularization for PAD during the study interval. Most were men (64·6 per cent) and the median age was 71 (i.q.r. 62-78) years. Following endovascular revascularization, the 5-year cumulative incidence of amputation was 4·2 per cent in patients with intermittent claudication and 18·0 per cent in those with a record of tissue loss. The corresponding rates were 10·8 and 25·3 per cent respectively after open revascularization, and 8·1 and 25·0 per cent after combined procedures. The 5-year cumulative incidence of death varied from 24·5 to 39·8 per cent, depending on procedure type. Competing risks methods consistently produced lower estimates than standard methods. CONCLUSION: The 5-year risk of major amputation following lower limb revascularization for PAD appears lower than estimated previously. Patients undergoing revascularization for tissue loss and those who require an open procedure are at highest risk of limb loss.

Topical oxygen therapy promotes the healing of chronic diabetic foot ulcers: a pilot study.

OBJECTIVE: Interventions that can heal or reduce diabetic foot ulcer (DFU) size may reduce the incidence of infection and amputation, and reduce associated social and economic costs. Many chronic wounds exhibit a degree of hypoxia and this leads to a reduction in healing processes including cell division and differentiation, angiogenesis, infection prevention, and collagen production. The aim of this pilot study was to assess the effects of a device supplying continuous oxygen ambulatory therapy on healing in chronic DFUs. METHOD: Patients with chronic DFUs from two tertiary referral hospitals in the UK received treatment with the device. Data were prospectively obtained on wound size using standardised digital images measured by a clinician blinded to the study. Data on device satisfaction and pain were also obtained. RESULTS: We recruited 10 patients, with a mean ulcer duration of 43 weeks (median: 43 weeks) before treatment. By week eight, mean ulcer size had decreased by 51% (median: 53%). Seven of the 10 ulcers were in a healing trajectory, one ulcer present for 56 weeks healed completely, a two-year old ulcer was reduced by more than 50%, and a third, present for 88 weeks, was down to 10% of its original size by the end of the eight-week study. There was also a non-significant trend towards reduction in pain and the device was extremely well tolerated. CONCLUSION: The ambulatory topical oxygen delivery device showed a significant beneficial effect on wound size. This poses practical advantages over currently existing oxygen-based wound therapies such as hyperbaric oxygen therapy due to its continuous oxygen delivery, ease of use, safety and lower cost. The results of this study warrant further review of the device in comparison to standard wound therapies.

Weekend effect in non-elective abdominal aortic aneurysm repair.

BACKGROUND: The 'weekend effect' describes the phenomenon where patient outcomes appear worse for those admitted at the weekend. It has been used recently to justify significant changes in UK health policy. Recent evidence has suggested that the effect may be due to a combination of inadequate correction for confounding factors and inaccurate coding. The effects of these factors were investigated in patients with acute abdominal aortic aneurysm (AAA). METHODS: Patients undergoing non-elective AAA repair entered into the UK National Vascular Registry from January 2013 until December 2015 were included in a case-control study. The patients were divided according to whether they were treated during the week (Monday 08.00 hours to Friday 17.00 hours) or at the weekend. Data extracted included demographics, co-morbidities, preoperative medications and baseline blood test results, as well as outcomes. Coding issues were investigated by looking at patients treated for ruptured, symptomatic or asymptomatic AAA within the non-elective cohort. The primary outcome was in-hospital mortality. Secondary outcomes included length of inpatient stay, and cardiac, respiratory and renal complications. RESULTS: The mortality rate appeared to be higher at the weekend (odds ratio (OR) 1·69, 95 per cent c.i. 1·47 to 1·94; P < 0·001), but this effect disappeared when confounding factors and coding issues were corrected for (corrected OR for ruptured AAA 1·09, 0·92 to 1·29; P = 0·330). Differences in outcomes were similar for prolonged length of hospital stay (uncorrected OR 1·21, 95 per cent c.i. 1·06 to 1·37, P = 0·005; corrected OR for ruptured AAA 1·06, 0·91 to 1·10, P = 0·478), and morbidity outcomes. CONCLUSION: After appropriate correction for confounding factors and coding effects, there was no evidence of a significant weekend effect in the treatment of non-elective AAA in the UK.

A systematic review of postoperative cognitive decline following open and endovascular aortic aneurysm surgery.

OBJECTIVES Postoperative cognitive decline (POCD) is a well-recognised neurological phenomenon following major surgery. Most commonly seen in elderly patients, it has direct links to increased long-term morbidity and reduced quality of life. Its incidence following open and endovascular abdominal and thoracic aneurysm surgery is unclear. The purpose of this systematic review is to collate available evidence for POCD following abdominal and thoracic aortic surgery, and to identify continuing controversies directing future research. METHODS A MEDLINE search was conducted following the recommendations of the PRISMA guidelines. Terms searched for included but were not limited to: aortic surgery, delirium, postoperative cognitive decline/dysfunction thoracic aortic surgery, abdominal aortic surgery. Reference lists were searched for additional studies. RESULTS Five observational studies were identified from the literature search. Variation in study methods, cognitive test batteries and thresholds set by the study coordinators did not allow for pooled results. In those studies that did find evidence of decline, risk was linked to age over 65 years, presence of postoperative delirium and decreased years in education. CONCLUSIONS Evidence thus far suggests that POCD can affect patients following major aortic, non-cardiothoracic as well as cardiothoracic surgery. Future research should focus on using a validated repeatable battery of cognitive tests and a single defined threshold for POCD to allow pooled analysis and more robust conclusions. Larger, adequately powered studies are required to re-evaluate the effect of aortic aneurysm surgery on postoperative cognitive function.

Extended use of endovascular aneurysm sealing: Chimneys for juxtarenal aneurysms.

Hostile infrarenal aortic neck anatomy presents a challenge for the endovascular treatment of abdominal aortic aneurysm. Open surgical repair has been seen as the gold standard treatment for juxtarenal abdominal aortic aneurysm; however, endovascular techniques are now becoming more prevalent, particularly in patients deemed high risk for morbidity and mortality with open repair. The morphology of an aneurysm is a determinant of long-term outcomes, and short aneurysm necks are associated with poorer outcomes and a higher rate of secondary reinterventions. Parallel grafts have been used in combination with endovascular aneurysm repair to elongate the sealing zone into the paravisceral segment of the aorta. This technique is associated with a risk of proximal Type I endoleak due to "guttering." This risk may be decreased when parallel grafts are used in combination with endovascular aneurysm sealing and, as such, this technique may represent an alternative to current techniques for the treatment of juxtarenal abdominal aortic aneurysm, such as the use of conventional bifurcated grafts (with or without parallel grafts) and fenestrated endovascular stent grafts.

The Endovascular Sealing Device in Combination with Parallel Grafts for Treatment of Juxta/Suprarenal Abdominal Aortic Aneurysms: Short-term Results of a Novel Alternative.

BACKGROUND: The chimney technique using parallel grafts offers an alternative to fenestrated or branched endovascular solutions for juxtarenal and suprarenal aneurysms. Endograft deployment proximal to the renal or visceral ostia is combined with parallel stents to the aortic side branches. Application of the chimney technique using the Nellix device (Ch-EVAS) may offer some potential advantages with respect to the seal between the endograft and the parallel grafts. This study aimed to investigate the feasibility and efficacy of the Nellix endovascular aneurysm sealing (EVAS) system in conjunction with parallel grafts for the treatment of juxtarenal and suprarenal aneurysms. METHODS: A prospective evaluation of patients treated for juxtarenal and suprarenal non-ruptured aortic aneurysms using Ch-EVAS was undertaken in a single vascular unit. Patients were treated with this technique if they were unsuitable for either open repair or a custom-made complex branched/fenestrated endograft. Procedural, postoperative morbidity, and mortality data were recorded. RESULTS: Between March 2013 and April 2015, 28 patients were treated with Ch-EVAS. The median age was 75 years (range 60-87 years) and the median aneurysm diameter 66 mm (IQR 60-73 mm). Eight patients underwent suprarenal aneurysm repair including parallel grafts in the superior mesenteric artery and renal arteries. Five patients had a double chimney configuration; all the other patients were treated with a single chimney configuration. There was one 30-day or in-hospital mortality in a patient with a symptomatic aneurysm (4%) and three further deaths within 1 year of follow-up. One proximal type I endoleak and one type II endoleak occurred. Four patients underwent a reintervention. One patient experienced a transient ischemic attack and two patients suffered from a minor stroke (7%), therefore the total number of cerebrovascular complications was 11%. No patient required postoperative renal replacement therapy. CONCLUSIONS: Ch-EVAS appears to offer a feasible solution for juxtarenal and suprarenal aneurysms with adverse morphology. In this short-term follow-up endoleak rates were low and re-intervention rates were acceptable. Outcomes over extended follow-up will determine the application of this novel technique and better define which patients and aneurysm morphology can be treated effectively.

Editor's Choice - Delays to Surgery and Procedural Risks Following Carotid Endarterectomy in the UK National Vascular Registry.

OBJECTIVE: Guidelines recommend that patients suffering an ischaemic transient ischaemic attack (TIA) or stroke caused by carotid artery stenosis should undergo carotid endarterectomy (CEA) within 14 days. METHOD: The degree to which UK vascular units met this standard was examined and whether rapid interventions were associated with procedural risks. The study analysed patients undergoing CEA between January 2009 and December 2014 from 100 UK NHS hospitals. Data were collected on patient characteristics, intervals of time from symptoms to surgery, and 30-day postoperative outcomes. The relationship between outcomes and time from symptom to surgery was evaluated using multilevel multivariable logistic regression. RESULTS: In 23,235 patients, the median time from TIA/stroke to CEA decreased over time, from 22 days (IQR 10-56) in 2009 to 12 days (IQR 7-26) in 2014. The proportion of patients treated within 14 days increased from 37% to 58%. This improvement was produced by shorter times across the care pathway: symptoms to referral, from medical review to being seen by a vascular surgeon, and then to surgery. The spread of the median time from symptom to surgery among NHS hospitals shrank between 2009 and 2013 but then grew slightly. Low-, medium-, and high-volume NHS hospitals all improved their performance similarly. Performing CEA within 48 h of symptom onset was associated with a small increase in the 30-day stroke and death rate: 3.1% (0-2 days) compared with 2.0% (3-7 days); adjusted odds ratio 1.64 (95% CI 1.04-2.59) but not with longer delays. CONCLUSIONS: The delay from symptom to CEA in symptomatic patients with ipsilateral 50-99% carotid stenoses has reduced substantially, although 42% of patients underwent CEA after the recommended 14 days. The risk of stroke after CEA was low, but there may be a small increase in risk during the first 48 h after symptoms.

Endovascular aneurysm sealing for infrarenal abdominal aortic aneurysms: 30-day outcomes of 105 patients in a single centre.

OBJECTIVE: Endovascular aneurysm sealing (EVAS) has been proposed as a novel alternative to endovascular aneurysm repair (EVAR) in patients with infrarenal abdominal aortic aneurysms (AAA). The early clinical experience, technical refinements, and learning curve of EVAS in the treatment of AAA at a single institution are presented. METHODS: One-hundred and five patients were treated with EVAS between March 2013 and November 2014. Prospective data were recorded on consecutive patients receiving EVAS. Data included demographics, preoperative aneurysm morphology, and 30-day outcomes, including rates of endoleak, limb occlusion, reintervention, and death. Postoperative imaging consisted of duplex ultrasound and computed tomographic angiography. RESULTS: The mean age of the cohort was 76 ± 8 years and 12% were female. Adverse neck morphology was present in 72 (69%) patients, including aneurysm neck length <10 mm (20%), neck diameter >32 mm (18%), ß-angulation >60° (21%), and conical aneurysm neck (51%). There was one death within 30 days. The incidence of Type 1 endoleak within 30 days was 4% (n = 4); all were treated successfully with transcatheter embolisation. All four proximal endoleaks were associated with technical issues that resulted in procedure refinement, and all were in patients with adverse proximal aortic necks. The persistent Type 1 endoleak rate at 30 days was 0% and there were no Type 2 or Type 3 endoleaks. Angioplasty and adjunctive stenting were performed for postoperative limb stenosis in three patients (3%). CONCLUSIONS: EVAS appears to be associated with reasonable 30-day outcomes despite the necessity of procedural evolution in the early adoption of this technique. EVAS appears to be applicable to patients with challenging aortic morphology and endoleak rates should reduce with procedural experience. The utility of EVAS will be defined by the durability of the device in long-term follow-up, although the absence of Type 2 endoleaks is encouraging.

Symptomatic Renal Artery Stenosis and Infra-renal AAA.

OBJECTIVES: To identify evidence to guide the vascular surgeon as to the relevance of renal artery stenting in a patient with symptomatic renal artery stenosis undergoing elective endovascular aortic aneurysm repair (EVAR). METHODS: A comprehensive literature search of MEDLINE was performed without time limits. The following terms were used in the first instance: renal artery stenting and renal artery stenosis, and any other analogous terms identified during the search. Selection criteria were set to randomised control trials. RESULTS: Despite several large, randomised controlled trials investigating renal artery stenting against medical treatment alone in symptomatic renal artery stenosis, there has been no significant benefit identified in terms of improvement in renal function, control of blood pressure, or need for dialysis. The stented populations were also more likely to suffer from complications caused by the procedure such as bleeding, cholesterol embolisation and flash pulmonary oedema. CONCLUSION: There is no evidence for the use of renal artery stenting over optimal medical management in the treatment of patients with symptomatic atherosclerotic renal artery stenosis, irrelevant of the degree of stenosis. In the setting of EVAR, prevention of deterioration of renal function should be with involvement of the renal physicians, adequate hydration, and use of minimal contrast agent. Repair should be undertaken in centres with access to 24-hour haemofiltration services.

International validation of a risk score for complications and reinterventions after endovascular aneurysm repair.

BACKGROUND: Lifelong surveillance is considered mandatory after endovascular repair (EVAR) of abdominal aortic aneurysms to detect endograft complications and prevent aneurysm rupture. Current protocols are not cost-effective or clinically effective. The international validity of the St George's Vascular Institute (SGVI) score for EVAR complications was examined. METHODS: The ENGAGE registry recruited patients undergoing EVAR at 79 centres in 30 countries. Reinterventions and endograft complications were recorded for up to 3 years after surgery. Preoperative aneurysm morphology was extracted from the registry database, and used to predict whether patients would be at low or high risk of complications after EVAR based on the SGVI score. Kaplan-Meier analysis was used to compare the incidence of endograft complications and reinterventions in patients predicted to be at low risk compared with those predicted to be at high risk. RESULTS: Some 1207 patients underwent EVAR, with follow-up of up to 3 years. The SGVI score accurately discriminated freedom from reinterventions (90·5 versus 79·3 per cent in low- versus high-risk patients; P < 0·001), freedom from endograft complications (77·9 versus 69·6 per cent in low- versus high-risk patients; P = 0·012), and freedom from a composite outcome measure of reinterventions or endograft complications (75·0 versus 66·1 per cent in low- versus high-risk patients; P = 0·006) during mid-term follow-up. CONCLUSION: This study has provided international validation of a morphological risk score that predicts mid-term reinterventions and endograft complications. The results may enable risk-stratified surveillance after EVAR.

Carotid artery stenting: high-risk interventionist versus high-risk center.

Carotid artery stenting (CAS) is a less invasive alternative to carotid endarterectomy (CEA) for the management of carotid artery stenosis. Although early multicenter randomized controlled trials reported inferior results for CAS compared with CEA, recent advances in technology and increasing CAS operator expertise have lead to improved results. As with any procedure, a high caseload translates into increased experience and better outcomes. This article discusses the current shortfalls of CAS, as well as the various options available to improve CAS results. The majority of studies suggest that there is an inverse relationship between caseload volume and CAS outcomes that defines high-risk interventionists and high-risk centers. Centralizing CAS procedures to high-volume centers is essential for optimization of CAS outcomes.

Rationalising cross-match requests in vascular surgery is safe and cost effective.

This study describes how a vascular centre rationalised their blood transfusion policy. A multidisciplinary panel reviewed data for blood transfusion protocols and implemented improvements that were analysed. The number of units cross-matched fell from 272 to 183 over a six month period. Unused blood reduced from 80% to 61%. The study concluded that rationalisation of cross matching policies is safe and provides cost and resource benefits.

Current endovascular management of acute type B aortic dissection - whom should we treat and when?

Aortic dissection is the most common of the acute aortic syndromes, once initiated, intimal disruption can propagate in an anterograde or retrograde fashion, and the resulting false lumen may compress the ostia of aortic branches or cause aortic expansion and eventual rupture. Acute complicated type B dissection most often requires immediate interventional treatment, whereas uncomplicated dissection has classically been managed with medical therapy alone. The first line management of complicated acute and aneurysmal chronic type B dissections has shifted toward minimally invasive endovascular treatment. To give an overview of the contemporary management of acute type B dissection, clinical manifestations, aims of management, and therapeutic options are discussed in the context deciding which patients require intervention and when.

Transgene delivery to endothelial cultures derived from porcine carotid artery ex vivo.

Carotid artery disease is a widespread cause of morbidity and mortality. Porcine models of vascular disease are well established in vivo, but existing endothelial systems in vitro (e.g. human umbilical vein endothelial cells, rat aortic endothelial cultures) poorly reflect carotid endothelium. A reliable in vitro assay would improve design of in vivo experiments and allow reduction and refinement of animal use. This study aimed (1) to develop ex vivo endothelial cultures from porcine carotid and (2) to test whether these were suitable for lentivector-mediated transgene delivery. Surplus carotid arteries were harvested from young adult female Large White pigs within 10 min post-mortem. Small sectors of carotid artery wall (approximately 4 mm×4 mm squares) were immobilised in a stable gel matrix. Cultures were exposed to HIV-derived lentivector (LV) encoding a reporter transgene or the equivalent integration-deficient vector (IDLV). After 7-14 days in vitro, cultures were fixed and labelled histochemically. Thread-like multicellular outgrowths were observed that were positive for endothelial cell markers (CD31, VEGFR2, von Willebrand factor). A minority of cells co-labelled for smooth muscle markers. Sensitivity to cytotoxic agents (paclitaxel, cycloheximide, staurosporine) was comparable to that in cell cultures, indicating that the gel matrix permits diffusive access of small pharmacological molecules. Transgene-expressing cells were more abundant following exposure to LV than IDLV (4.7, 0.1% of cells, respectively). In conclusion, ex vivo adult porcine carotid artery produced endothelial cell outgrowths that were effectively transduced by LV. This system will facilitate translation of novel therapies to clinical trials, with reduction and refinement of in vivo experiments.

Embolisation of type 2 endoleaks after endovascular aneurysm repair.

Endovascular treatment has become the preferred method of repair of abdominal and thoracic aortic aneurysms, and comes with a unique complication in the form of endoleaks (type I-IV). Type II endoleaks are the focus of this review. They are the most common form of endoleak detected in CT surveillance following endovascular repair. They are observed in 9% to 30% of patients after abdominal endovascular repair (EVR), and 1.4% following thoracic endovascular aortic repair (TEVR). They are classified as primary or secondary, depending on when they are identified following EVR. Typically, retrograde filling of the aneurysm sac is caused by single or multiple, patent feeding vessels. Despite its relative frequency, there is a lack of consensus on the threshold at which treatment should be considered. The aims of treatment are to halt sac expansion or to prevent rupture. A majority of patients may be managed conservatively. In those that are treated, the most common form of management is single vessel embolization. As we will discuss here, there are several ways of performing this procedure, based on the site of endoleak, and causative vessel. Possible reasons for poor success rates will also be discussed. A general consensus on how to best manage these patients is yet to be reached. The aim of this review is to give an overview of type II endoleaks, their natural history and vessels most commonly involved, as well as different approaches to embolisation.